Method of producing colored photographic materials



Patented Feb. 8, 1938 UNITED STATES- METHOD OF PRODUCING COLORED PHOTO- GRAPHIC MATERIALS Bla Gaspar, Brussels, Belgium No Drawing. Application August 9, 1934, Serial' No. 739,136. In Germany August 10, 1933 6 Claims.

It is known to produce photographic materials, which contain an insoluble deposit of a dyestufl with a metal. The production of photographiclayers of this nature has not been practicable heretofore, as it hasbeen necessary to introduce the dyestuil into the layer in some complicated manner, or else it has been necessary tov produce the dyestuii deposit in the emulsion colloid by way of double conversion, it then being necessary to remove-from the layer the products of this double conversion.

This invention relates to a simple and economical method of producing colored photographic materials, in which the substances necessary for the conversion may be introduced into the photographic emulsion without any detrimental effeet.

This isaccomplished according to the invention by the use of salts of organic acids of that kind in which the anion is unable to act adversely in the photographic layer. Primarily there will be employed salts of metals or organic bases, the cations of which are indifferent in respect to the emulsion, and which result in deposits which are not diffusing, with lake-forming dyestufis, for example I may use alkaline earth salts, magnesium salts, or certain nitrogenous bases as set forth in my co-pending application now Patent No. 2,046,067, June 30th, 1936.

An additional advantage consists in the fact that I may use the salts of weak acids such as areadmirably suitable for puffing of the layer and act favorably on the 'sensitiveness. oi the light sensitive layers. vSuitable anions for the salts are weak organic acids, such as acetic acid, .propionic acid, butyric acid, caproic acid, acrylic acid, malic acid, adipic acid, naphthaline sulphonic acid, maleic acid, aminic acid.

.For example, there is admixed with 1 litre of photographic silver bromide emulsion 5 grammes of Chrysophenine G (No. 304 Schultz Farbstoiitabellen 5th edition 1920, published by Weidmann Buchhundlung). To this there are added 2 grammes of barium butyrate. On to a layer of this kind-there may be poured a second layer, which contains, for example, a red lake-forming dyestuff, such as Antosine BN (Fierz-David: 4

vention may also be employed in conjunction with.

separate layers which are situated above or below the light-sensitive layers.

It is accordingly also possible to pour filter layers free of emulsion serving forthe screening 'of photographic emulsion or as a base for photographic layers.

What I claim as new and desire to secure by Letters Patent is:

1. A method of uniformly coloring colloids used in the production of a photographic material including a light sensitive silver halide which comprises causingwithin the colloid a double decomposition by incorporating a lake forming dyestuff and a salt, which salt contains a lake forming cation and an anion of a colorless weak organic acid, indiiferent to the lightsensitive silver halide, a dyestufl lake being formed by the reaction and a salt of the weak organic acid resulting as a by-product.

2. A method of uniformly coloring light sensitive silver halide emulsions for photographic purposes which comprises causing within the emulsion a double decomposition by incorporating a lake forming dyestufl and a salt, which salt contains a lake forming cation and an anion of a colorless weak organic acid, indifferent to the light sensitive emulsion, a dyestufi lake being formed by the reaction and a salt of the weak organic acid resulting as a by-product.

3. A method of uniformly coloring colloids to form a colored layer adjacent to a light sensitive silver halide layer in a photographic material which comprises causing within the colloid a double decomposition by incorporating a lake forming dyestufl and a salt, which salt contains a lake forming cation and an anion of a colorless weak organic acid indifierent to the light sensitive layer, a dyestuif lake being formed by'the reaction and a salt of the weak organic acid resulting as a by-product. I

4. A method of uniformly coloring light sensitive silver halide emulsions for photographic purposes which comprises causing within the emulsion a double decomposition by incorporating a dyestufi, Chrysophenine G, and barium butyrate to form a dyestufl lake.

5. A method of uniformly coloring light sensitive silver halide'emulsions for photographic purposes which comprises causing within the emulsion 9. double decomposition by incorporating a dyestuff, Antosine RN, and barium butyrate to form a dyestufi lake.

8. A method of uniformly coloring light sensitive silver halide emulsions for photographic purposes which comprises causing within the emulsion a-double decomposition by incorporating a dyestuif, Diamine Pure Blue FF, and adipic guanidine, to form a dyestufl lake.

. BELA GAsPAR. 

